Liquid dispensing device



M. A. GILMAN LIQUID DISPENSING DEVICE Filed Oct. 7,1955

May 14, 1957 INVENTOR.

MARVIN A. GILMAN BY M Mr ATTORNEY jflled i.l

LIQUID DISPENSING DEVICE Application October 7, 1955, Serial No. 539,046

Claims. (Cl. 222-309) This invention relates to liquid dispensing andmeasuring devices. More particularly, the invention concerns pipettes,burettes, syringes and the like, for dispensing accurately measuredquantities of liquid. Such devices are used in scientific and medicalwork where chemical titrations, serological tests and other researchactivities require means for precisely and rapidly measuring anddispensing quantities of liquid.

Basically, such devices may comprise a barrel and a plunger reciprocabletherein, and operable to draw a predetermined quantity of liquid intothe barrel upon a determined movement of the plunger outwardly of thebarrel, followed by dispensation of the liquid from the barrel uponinward movement of the plunger.

It has been proposed to provide such devices with means for adjustablysetting the movement of the plunger relative to the barrel so as toallow rapid dispensing of a large number of equal quantities of liquid.However, such means known in the art have been found to be ofcomplicated construction, ditcult to manipulate and adjust, or a sourceof interference with the reciprocatory movement of the plunger in thebarrel.

Accordingly, one object of this invention is to provide a device of thecharacter described, which includes means extending between the barreland plunger of the device for adjustably limiting the relative movementtherebetween, yet being of a construction which does not interfere withthe normal reciprocatory movement of the plunger in the barrel.

Another object of this invention is to provide for use with a liquiddispensing device, means for adjustably determining the amount of liquidto be dispensed therefrom, such means comprising a minimum number ofcomponents which lend themselves to rapid assembly or disassembly or maybe so disposed as to allow the device to be used in a conventionalmanner free of the adjusting means.

Still another object of this invention is to provide an assembly ofcomponents for mounting on the relatively movable parts of a syringe toregulate the relative movement of such parts, together with adapters foraccommodating the assembly to syringes of a wide range of sizes.

Other objects of this invention will in part be obvious and in parthereinafter pointed out.

In the drawing, Fig. l is a front elevational view of a syringeembodying an assembly embodying the invention; Fig. 2 is a sideelevational view thereof in section;

Fig. 3 is a top plan view of an assembly component attachable to thesyringe plunger;

Fig. 4 is a bottom plan view of an assembly component attachable to thesyringe barrel;

Fig. 5 is a vertical sectional view thereof showing the use of adaptermembers; and

Fig. 6 is a vertical sectional view of the component shown in Fig. 3,illustrating the use of adapter members therefor.

2,792,157 Vii'atenteci Maty 14, 1957 Referring in detail to the drawingand particularly Figs. l and 2, 10 designates an assembly embodying theinvention, mounted on a liquid dispensing device such as a syringe 11.The syringe 11 comprises the usual tubular barrel 12 having a dispensingtip 13 at the lower end thereof and a radial ange 14 at the upper endthereof. A plunger 15 is reciprocably mounted in the barrel 12, theplunger 15 having a radial flange 16 at the upper head portion 17thereof. The barrel 12 and plunger 15 may be formed of glass or othersuitable materials in a manner known in the art.

The assembly 10 is operative to adjustably set the relative movement ofthe plunger 15 and barrel 12 to accurately determine the amount ofliquid drawn up yintothe barrel on the up stroke of the plunger, fordispensing from tip 13 on the down stroke of said plunger.

The assembly 10 comprises an internally threaded cupped member 18 havinga bottom wall 19 formed with a central opening 20 for receiving the headportion 17 of plunger 15, the flange 16 thereof resting on the innersurface of wall 19. A screw 21 with a flanged head 22 is screwed intomember 18 to hold the same rmly on plunger 15. The member 18 furthercomprises a lug 23 extending horizontally from the upper end of sidewall 24 thereof, the lug being formed with a slot 25 opening on one sidethereof, for the purpose later described.

The assembly 10 further includes another internally threaded cuppedmember 26 having a bottom wall 27 formed with a central opening 28for-receiving the barrel 12, the barrel ange 14 resting on the innersurface of wall 27. An externally threaded cylindrical member 29 havinga bottom wall 30 formed with a central opening 31, is screwed intomember 26 to hold the same firmly on barrel 12, the opening 31registering with the open end of the barrel and allowing the plunger 15to pass therethrough freely.

The cupped member 26 further includes a horizontally extending loopedmember 32 at the lower end of side wall 33 thereof, said member 32forming an elongated guide opening 34. Also extending horizontally fromthe lower end of side wall 33 of member 26 are diametrically aligned,down turned finger grips 35 which are disposed parallel to thelongitudinal axis of opening 34.

A coiled spring 36 is disposed concentrically about plunger 15 with itslower end received in member 26, fitting snugly against the innersurface of side wall 33 and bottom wall 30. The upper end of spring 36closely engages the outer surface of side wall 24 of member 18 and angedend 24a thereof, thus resiliently biasing the plunger 15 to itsoutermost position in barrel 12 and restoring the plunger to saidposition each time the plunger is pressed inwardly into the barrel by athumb applied to screw head 22 while barrel 12 is supported by fingersapplied beneath grips 35.

A threaded rod 37 is located parallel to the longitudinal axis ofsyringe Y11, with the upper end thereof passing through lug slot 25 inmember 18; nuts 38, 38a on either side of lug 23 locking the rod inplace. The lower end of rod 37 passes freely through guide opening 34and in spaced relation to member 32 and side wall 33 of member 26. Apair of nuts 39, 39a are screwed onto the lower end of rod 37 belowmember 32, the nuts spanning guide opening 34.

It will be apparent that nut 39, movable longitudinally on rod 37 andlocked in place by nut 39a, forms an adjustable stop engageable withabutment means formed by the underside of member 32, to accuratelydetermine the limits of the movement of plunger 15 outwardly of barrel12 under the bias of spring 36. In this way,

the Heflective volume of barrel 12 measured by the position of `the tipof plunger 1S ,at its determined outermost position, is precisely setand each time the plunger is operated to ll the barrel, the identicalamount of liquid will bedispensedfrom barrel tip 13, on which a needleor other liquid transferring means, not shown, may be mounted.

.While the upper end of rod `37is clamped to member 18, the lower end ofsaid rod,mo.v,es freelyrelativeto member 26 on barrel 12, thus avoidinganyy binding action between plunger 15 and barrel 12 which might accruefrom a rigid interconnection of the parts ofassembly 1 0, which in turnare mounted ,on Vsaid plunger and barrel. Also, plungerlS maybe rotatedvabout its Vaxis within barrel 12, within.the ,limits of thelongitudinal extent. ofsuide opening `3ft lfdesired, rod37 maybe quicklydisconnected from member 18 by` loosening nuts 38, 38z and sliding theupper en d of the rod out of lu'g slot 25, thusallowing syringe 11 to beused in the conventionalmanner without the benefit of the stop means.The rod 37 may be altogether removed from the assembly by removing thenuts therefrom at either end thereof and slipping the rod o ut of Vguideopening 34.

The openings Vin `cupped members.18, 26 are ofa size to accommodate thebarrel and vplunger of an average size syringe. Eeans is provided foradapting the assembly 10 for use with small capacity syringes havingsmalldiameter barrels and plungers.

Thus, as shown in ,-Fig. 5, an adapter disc .40 shouldered as at 41, ispositioned on wall 27 of member '26, the disc 'being formed with asmalldiameter Icentral opening 42 to receive the small sized barrel 12a, themember 29 screwed into member 26 engaging al washer 43 overlying thebarrel-flange 14a, to hold the member 26 firmly on said barrel 12a.

Also, as shown in Fig. 6, a plunger adapter in the form of a cup shapedmember 44 having a'radial ange 45 at the upper en d thereof, ismountedinmember 18 in depending relation thereto, by means of said ang'e 45. Thebottom wall of `adapter .44 is formed lwith a smallv diameter opening 46to pass plunger 1 5,a and to seatgthe flange 16a thereof. Theplunger 15aYis held firmly in place on member 18 by means of v.a plug .47dispose/dbetween the plunger flange 16a land the screw 21 Von memberl18. Such Yarrangement allowsmaximum utility of thelongitudinalextento'f plunger 15a relative to barrel 12a.

lt will thus be seen that there has been provided an improved lliqtnd`dispensing device in which the"severa1 objects lof the invention areachieved, and. which is well adaptedto lmeet the ,conditions ,ofpracticalllSe.

As` variouschangesjmight be made inthe embodiment ofthe invention hereindescribed, without departing from thespirit thereof, it is understoodthatall 'matter herein shown londescribed, shall be deemed illustrativeandnot by way of limitation, except ,assetn forth in the appendedclaims.

Having vthus disclosed my invention, I claim as new and desire toprotectby Letters Patent:

1. 41nc ombinatitm with ya liquidrdispensing--device `comprising acylindrical barrel yanda plungerreciprocably mounted therein, means yfor`regulating the Y travel of the plunger relative to the barrelcomprising a first member mounted on said barrel, asecond Amembermountedon said plunger, an elongated member extending between said rst andsecond members, means for clamping said elongated member to said secondmember, said first member including an abutment portion adjacent thelongitudinal extent of said elongated member and spaced therefrom forfreely passing said elongatedl member therethrough, and stop means`adjustably -mounted along the longitudinal extent of said .elongatedmember foren- `gagernent with the abutment. portion ofwsaidfirstmember,and spring means between said first, andv second members for urgingIsaid plunger out of said barrel and said stop means into engagementwith the abutment` portion of said first member.

2. In combination with a liquid dispensing device comprising a barreland a plunger reciprocably mounted therein, means for regulating thetravel of saidplunger in said barrel comprising a member mounted on saidbarrel, a member mounted on said plunger, lug means projecting from oneof said members, abutment means projecting from the other of saidmembers, an elongated member extending between said lug means and saidabutment means, means for removably securing said elongated member tosaid lug means, said abutment means being in spaced relation to-thelongitudinal extent of said elongatedvmember, stop means mounted formovement along the longitudinal extent of said elongated member toadjusted positions thereon for engagement with said abutment means, andspring means between said `first and second mentioned members.

3. The combination as in claim 2 `wherein said lug means is formed witha slot for removably receiving said elongated member therein, and saidyabutment lmeans comprises `a looped member forming a guide openingpassing said elongated member freely therethrough.

4. The combination as in claim 3 wherein said elongated member isthreaded, said securing means comprising nuts on said elongated memberdisposed on either side of said lug means, and saidlstop means comprisesa nut on said elongated member spanning theV guide opening in saidabutment means.

5. An assembly for use with a syringe including a barrel having a liangeat the upper end thereof and a plunger reciprocably mounted therein,said plunger having a-flanged head, said assembly comprising a pair ofcupped members respectively mounted on "the yflanged portionrof saidbarrel and the -anged head of Vsaid plunger', each of said cuppedmembers including a bottom wall formed with an opening, and adaptermeans for each cupped member :for varying the size of the openingtherein, a member 4fixed to one of said cupped members for conjointlongitudinal movement therewith, abutment means on the other cuppedymember in vspaced relation to the path of travel of said member, andadjustable stop means on saidv member for yengagement with said abutmentmeans.

References-Cited in theffile of this patent UNITED STATES PATENTS

